Komotini began life as a Byzantine Fortress built by the Emperor Theodosius in the 4th century AD. The ruins of this quadrangular structure can still be found northwest of the central square. It has several museums including the Archaeological, Byzantine and Folklore museums.

Komotini is a thriving commercial and administrative center. It is heavily centralized with the majority of commerce and services based around the historical core of the city. The old commercial center is very popular with tourists as it houses traditional shops and workshops that have long vanished from other Greek cities.

In addition, in the northwestern outskirts of the city (Nea Mosinoupoli) locals and tourists alike flock into a modern shopping plaza, the Kosmopolis Park, which houses department stores, shops, supermarkets, a cinema complex, cafe and restaurants. The area stretching from Kosmopolis to Ifaistos is gradually becoming a retail destination in its own right.